1. Field of the Invention
The invention pertains to the field of pin mechanisms. More particularly, the invention pertains to a pin mechanism for releasing a pin.
2. Description of Related Art
FIGS. 1-2 show a prior art solenoid actuator in a released position and an unreleased position respectively.
The solenoid actuator has a housing 101 with a first bore 102 for slidably receiving a release pin 117 and a second bore 120 for receiving a solenoid assembly 121.
The release pin 117 has a collar 122 that slides along the surface of the first bore 102 of the housing 101 and a shaft portion 123 that is slidably received within a cap 103 closing off the first bore 102 of the housing 101. A release spring 106 is present between the release pin 117 and the cap 103.
Between the collar 122 and the shaft portion 123 of the release pin 117 is a neck portion 124. A ramp section or angled surface 125 is present between the collar 122 and the neck portion 124 of the release pin 117.
Slidably received within an open bore 107 of the neck portion 124 of the release pin 117 is a detent retainer 114. The detent retainer 114 has an inner surface defining a bore 118 for receiving a release spool 109. The inner surface of the bore 118 of the detent retainer 114 includes a straight surface 126 which is connected to an angled ramp section 119.
The release spool 109 has a cavity 127 which receives a first ball bearing 115a attached to a second ball bearing 115b through a retention spring 116. The release spool 109 is also coupled to a first end 113a of a push rod 113.
The solenoid assembly 121 received within the second bore 120 of the housing 101 includes at least one coil 111 connected to a power source (not shown), a solenoid spool 110, and a moveable armature 112. Connected to the moveable armature 112 is a second end 113b of a push rod 113.
In the unreleased position, as shown in FIG. 2, the collar 122 of the release pin 117 is not in contact with the end of the first bore 102 and the release spring 106 is compressed between the collar 122 of the release pin 117 and the cap 103. The release pin 117 is maintained in this position by the first and second ball bearings 115a, 115b engaging the angled surface 125 of the collar 122 of the release pin 117 and the flat surface 126 of the detent retainer 114 . The first and second ball bearings 115a, 115b are held against the angled surface 125 of the collar 122 and the straight surface 126 of the detent retainer 124 by the retention spring 116.
To move the solenoid actuator to a released position as shown in FIG. 1, at least one coil 111 of the solenoid assembly 121 is energized and pulls the armature 112 away from the cap 103. Movement of the armature 112 moves the push rod 113 away from the cap 103, pulling the release spool 109 away from the cap 103. The movement of the release spool 109 allows the first and second ball bearings 115a, 115b to travel from the straight surface 126 of the detent retainer 114 to the ramp section 119 of the detent retainer 114, compressing the retention spring 116 between the ball bearings 115a, 115b. The movement of the first and second ball bearings 115a, 115b to the ramp section 119 of the detent retainer 114 removes any force on the collar 122 of the release pin 117, allowing the release spring 106 to move the release pin 117 to a position where the collar 122 is in contact with the end of the first bore 101.
The solenoid actuator of FIGS. 1-2 is resettable by moving the shaft portion 123 of the release pin 117 in a direction away from the solenoid assembly 121. The movement of the shaft portion 123 of the release pin 117 in this direction allows the retention spring 116 to bias the ball bearings 115a, 115b outwards to contact the ramp section 125 of the detent retainer 114 and to eventually come in contact with the angled surface 125 of the collar 122 of the release pin 117 as shown in FIG. 2.
It should be noted that there is not a bias force that acts directly on the push rod 113 that moves the armature 112 of the solenoid assembly 121.
FIG. 3 shows another prior art solenoid actuator in an unreleased position. The solenoid actuator has a housing 201 with a first bore 202 for slidably receiving a release pin 217 and a second bore 220 for receiving a solenoid assembly 221.
The release pin 217 has a collar 222 that slides along the inner surface of the first bore 202 of the housing 201 and a shaft portion 223 that is slidably received within a cap 203 closing off the first bore 202 of the housing 201. A release spring 206 is present between the release pin 217 and the cap 203.
Between the collar 222 and the shaft portion 223 of the release pin 217 is a neck portion 224. A ramp section or angled surface 225 is present between the collar 222 and the neck portion 224 of the release pin 217.
Slidably received within an open bore 207 of the neck portion 224 of the release pin 217 is a detent retainer 214. The detent retainer 214 has an inner surface defining a bore 218 for receiving a release spool 209. A circumferential groove 230 with straight edges 231 present along an outer surface of the detent retainer 214 and receive ball bearings 215. A compression spring 232 is present between the detent retainer 214 and the release spool 209, linking the detent retainer 214 to the release spool 209.
On the outer circumference of the release spool 209 is a groove section 234 including a ramp 235 between two straight surfaces 240, 241. The ball bearings may travel from straight surface 240 to the ramp 235 and come to rest on straight surface 241 as the release spool 209 slides within the bore 218 of the detent retainer 214. The detent retainer 214 is also coupled to a first end 213a of a push rod 213.
The solenoid assembly 221 includes at least one coil 211 connected to a power source (not shown), a solenoid spool 210, a moveable armature 212 and a stop 236. The second end 213b of the push rod 213 is connected to the moveable armature 212 and is slidably received by the stop 236. The movement of the armature 212 towards the release pin 217 is limited by the stop 236. Another compression spring 237, with the same spring force as the compression spring 232 between the detent retainer 214 and release spool 209 is present between the moveable armature 212 and the second bore 220 of the housing 201.
In an unreleased position, the collar 222 of the release pin 217 is not in contact with the end of the first bore 202 and the release spring 206 is compressed between the collar 222 of the release pin 217 and the cap 203. The release pin 217 is maintained in this position by the ball bearings 215 engaging the angled surface 225 of the collar 222 of the release pin 217, a straight edge 231 of the detent retainer 214, and a straight surface 240 of the groove section of the release spool.
To move the solenoid actuator to a released position (not shown), at least one coil 211 of the solenoid assembly 221 is energized and pushes the armature towards the cap 203. The movement of the armature 212 moves the push rod 213 towards the cap 203, pushing the detent retainer 214 and the release spool 209 towards the cap 203. The movement of the detent retainer 214 and the release spool 209 allows the ball bearings 215 to travel from the straight surface 240 to the ramp 235 and come to rest on straight surface 241 of the release spool 209. The movement of the ball bearings 215 to the ramp 235 of the release spool 209 removes any force on the collar 222 of the release pin 217, allowing the release spring 206 to move the release pin 217 to a position where the collar 222 is in contact with the end of the first bore 202.
The spring 232 between an end of the second bore 220 and the armature 212 provides a source of bias or spring force on the armature 212 that is specifically counteracted by the spring force of the spring 237 present between the release spool 209 and detent retainer 214. Therefore, a spring force that is in the direction of armature 212 movement that is not counteracted is not present.